A semiconductor memory device such as a DRAM has a great number of memory cells. Even if a failure occurs in only one memory cell, the entire semiconductor memory device may be determined as a bad product. However, if the entire semiconductor memory device is discarded as a bad product due to only one failed memory cell, the manufacturing yield would decrease. Thus, in a semiconductor memory device, a repair operation for replacing failed memory cells with redundancy memory cells is performed by a repair circuit so as to increase the manufacturing yield.